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From: Dan Cross <cross@math.psu.edu>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] OS install floppy hangs during boot on Bochs 1.4.1
Date: Wed, 27 Nov 2002 13:18:00 -0500	[thread overview]
Message-ID: <200211271818.gARII0w00432@augusta.math.psu.edu> (raw)
In-Reply-To: Your message of "Mon, 25 Nov 2002 22:56:54 MST." <20021125225654.B2266@tibia.amotlpaa.bogus>

> For my next trick... I wonder whether the MD5 algorithm is such
> that the hash for the concatenation of two blocks of bits can be
> determined quickly from the hashes for the two blocks.

Good God, I hope not.  MD5 shouldn't be a homomorphism.

> Then, you
> see, you could have the hash(es) for the invariant part(s) of the
> disk image lying around, and combine it (them) on the fly with the
> hash for the user's individual plan9.ini.

You could hash the hashes of the two bits, which would be
computationally cheap (relatively speaking).

	- Dan C.



  parent reply	other threads:[~2002-11-27 18:18 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-11-26  3:00 Russ Cox
2002-11-26  2:59 ` andrey mirtchovski
2002-11-26  5:56 ` Steven Taschuk
2002-11-26 10:25   ` Boyd Roberts
2002-11-27 18:18   ` Dan Cross [this message]
  -- strict thread matches above, loose matches on Subject: below --
2002-11-26  3:27 Geoff Collyer
2002-11-26  3:10 Russ Cox
2002-11-26  5:47 ` Steven Taschuk
2002-11-25 21:18 Russ Cox
2002-11-26  1:08 ` Steven Taschuk
2002-11-25 20:47 Steven Taschuk

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